Low frequencies carry an awful lot of energy and you will get maximum dynamic range out of a mic by close-micing but HPF'ing off the lows early in the chain. Many condensers have little preamps inside them, and the HPF may be placed before this pre giving it effectively a lot more headroom.

I don’t know how the U87 works, but some capsules can change response by adjusting polarization voltages.

You can boost your gain a lot higher if you throw out the bass early in the signal chain and preserve a much higher S/N ratio.

It’s because a HW circuit is easier to engage, more reliable, higher fidelity and requires less maintenance.

I don't know if you’ve worked with modern audio software but its truly a tangled stack of complexity, incompatibility, license management, etc etc. It can sound and work great once set up, but its touchy stuff when it comes time to make changes, update the OS, etc. as we all know software is notoriously buggy which is far from ideal in a live scenario.

Two contributing factors, I suspect. Most importantly software can only deal with whatever hits the digital side; physics and electronics being what they are there are lots of places to lose information on the analog side. If you filter out that range before you add gain you probably get way better SNR and don't have to rely on some ridiculously sampling and high resolution to not lose things. Second - they have been doing this a lot longer than sophisticated software pipelines have been available.

Software?

Software pipelines only began to get into radio some 20/25 years ago. NPR started in 71

Also software can't do magic (and you aren't processing each microphone digitally), you want to be your signal to be as best as it can as close to the source as you can make it to be.

Latency is still a problem with audio software.

Flippantly, because hardware is cool!

Plugins - software for audio programs - are available but audio engineers are famously persnickety.

Disagree, because the issue here is where the filter is. As others have noted that a condenser mic has an internal preamp, it is most useful to filter inside the mic before amplification to preserve S/N ratio. I suppose you could do that with software in the mic, but that seems like a lot of effort for maybe a worse result.

Further down the audio path it eventually makes sense to digitize, but if you didn't have the HPF in the mic your noise floor will be worse.

Reliability. Purpose-built hardware switches don't crash, ever.

Tell that to a roadie. Hardware fails all the time.

Old Steven king book. On a group traveling to a rain forest.

They gave all the equipment to a pack of monkeys for the night. Anything still working in the morning was certified as reliable.

I may be wrong (its been a long time since I read it, and it may be just something that fits really well thematically with the book but wasn’t actually in it), but I think that was Michael Crichton’s Congo, not a Steven King book.

Your right. That’s why I couldn’t find the reference

The original chaos monkeys?